Jim Lyon joined the powerhouse law firm of Murtha Cullina in 1955 and was a mainstay there until six years ago, when at the age of 81, he was told he'd have to leave for lack of space.

Lyon said the firm treated him “very well” and with respect during his nearly six decades there, but admits he “was not happy” about how his employment ended.

In a profession where acuity is a key asset, the implication is that this quality begins to wane after middle age.

And with that, comes tough business decisions for law firms and their staff.

“I was not happy, but I left,” said Lyon, now 87, who added he would have stayed on, if the firm had not told him it needed the space.

At the time, Lyon was serving out his final years at Murtha Cullina as of counsel, a title that many older attorneys hold at large law firms. Several lawyers acknowledge older practitioners are in danger of losing their livelihoods before they're ready to retire, but Lyon would not say whether he thought he was a victim of age discrimination. In fact, he repeatedly stressed he had no proof or could not make any assumptions that he was asked to leave because of his age.

“I had a small office and computer and they said they needed it for another attorney,” he said. “In retrospect, maybe it was very reasonable.”

This was also around the time his billable hours dropped about 70 percent, a death knell for his career. The attorney worked for Murtha Cullina representing tax-exempt organizations such as The Bushnell Center for the Performing Arts. But in the last few years, the firm assigned many of his clients to other people.

“Work was getting done by younger and younger partners,” he said. “I was getting older, though, and I was less productive. It's hard to stay up with the changes of laws like you used to.”

That inability could be costly for both the firm and attorney.

“If you are not making rain, and not bringing in clients, and not bringing in new people to the law firm, you will be moved out,” said Jack Tuter, chief judge of Florida's 17th Judicial Circuit and former director of the Florida Division of Alcoholic Beverages and Tobacco, ex-managing attorney for the American International Group and former partner at Stephens, Lynn, Klein, Lacava, Hoffman & Puya.

Law is often a profession with an expiration date, and in several states, including Connecticut and dozens of others, even judges, those who've reached the pinnacle of their careers, are forced to retire by 70.

Geraghty & Bonnano attorney Mark Dubois said there is often a conflict between older attorneys and their firms on separation dates and methods.

“I do see a tension,” said Dubois, 68, who served as chief disciplinary counsel for Connecticut from 2003 to 2011. “We senior people can be kind of cranky and difficult to manage and high-priced.”

But attorneys say firms appear to be reconsidering their approach to aging lawyers. While some maintain a mandatory retirement age of 70 for partners, many firms are beginning to soften their policy to retain talented lawyers who continue to perform.

“At the end of the day, it's a profession and a business and they want to make money,” Dubois said. “They also have to keep the pipeline open to young people.”

But for now, Mitchell & Sheahan partner Gary Phelan said age discrimination is a problem that will continue to grow because of the demographics of the profession.

“The whole concept in society, in general, is that retirement is becoming not as popular, as people are choosing not to retire,” he said.

Phelan has represented about half a dozen attorneys filing age discrimination lawsuits against their employers. But his clients have remained largely silenced by air-tight confidentiality agreements or fear that they'd lose work prospects if they spoke out against a law firm.

“Attorneys love what they do, unlike with people in some other professions,” which makes age discrimination especially difficult, he said. “If there is an arbitrary age where attorneys are told, 'You can't do that anymore,' they might not respond well.”